REFUSING TO UPGRADE DUE TO BEEN UNDER DEBT REVIEW

I have been a loyal client with Cell c for almost 17 years now. I have 3 contracts with them... My account has been up to date with no default in payments in these 17years. I have been under debt review for the past 10 years, I have always manage to upgrade with them. I am trying from last year December to upgrade. Unfortunately the upgrades department does not want to assist me with an upgrade for a handset... The words I am told is we not allowed to give new credit for people who are under debt review. I have try to reason with them that its not new credit but rather an upgrade. I want to know why am I now been discriminated as in the past while I was under debt review I was able to upgrade with no issues. As far as I am aware that a cellphone contract is a service agreement and not a credit agreement and one is allowed to upgrade the existing contract. They have now upgraded the sim and not a handset included when I phone the call center all they can do is give me a reference number and will investigate. I demand answers from you, I have been patient enough form December. CELL IS STOP TREATING LOYAL CUSTOMERS LIKE THRASH!!! AND STOP DISCRIMINATING LOYAL CUSTOMERS WHO ARE UNDER DEBT REVIEW, BUT THEIR ACCOUNTS ARE ALWAYS UP TO DATE.